Dolphin depredation is a significant problem for artisanal net fisheries worldwide. Interactions between dolphins and fishing nets can lead to entanglement, gear damage, and loss of catch. Although acoustic deterrents, such as dolphin anti-predation pingers, are widely used, they are costly. The objective of this study was to develop and assess the effectiveness of new low-cost devices to reduce depredation by common bottlenose dolphin (Tursiops truncatus) in artisanal fisheries in the Alboran Sea (Mediterranean). These innovative devices included recycled glass bottles and compact discs (CDs), based on the premise that they could impact the dolphins' echolocation sense. A total of 51 experimental fishing operations were conducted at depths ranging from 4 to 29 m off the coast of Malaga, Spain. Results indicate that the new low-cost bottle and CDs based devices had a deterrent effect on depredation by dolphins. A statistically significant logistic model was derived for the observed probability of depredation by dolphins in relation to the use of recycled glass bottles and CDs as acoustic mitigation devices. Limitations of these new low-cost devices are discussed, along with future research directions and their relationship to environmental and fisheries variables.
